According to an electric stapler included in a copier, a driver unit and a clincher unit are separated from each other upwardly and downwardly interposing a sheet table, and paper fed from a copying mechanism portion to a sheet table of an electric stapler is bound by a staple and thereafter discharged by passing an interval between the driver unit and the clincher unit.
Further, there is an electric stapler having a skewed binding function of moving the electric stapler at a vicinity of a corner portion of paper, rotating the electric stapler horizontally by 45 degrees and striking a staple in addition to a normal back binding function of striking a staple in parallel with a side of paper. There is posed a first problem that an electric stapler of this kind is provided with a motor for transverse movement and a motor for rotation, the mechanism is complicated, and in order to make rotational angles of the driver unit and the clincher unit separated upwardly and downwardly accurately coincide with each other, high accurate working of parts and adjustment in integration are needed and the cost is required therefor.
Further, a moving type electric stapler included in a copier is constituted such that a driver unit and a clincher unit are respectively engaged with two pieces of guide shafts arranged in parallel with each other and the driver unit and the clincher unit are moved in synchronism with each other by feeding means of a timing belt or a feed screw or the like.
The driver unit and the clincher unit of the moving type electric stapler of the background art are supported in air by the guide shafts. Therefore, there is posed a second problem that the guide shafts are bent by a reaction force in injecting and clinching a staple and when a number of sheets of paper is large and a striking load is large, a failure in penetrating a staple or buckling thereof or the like is brought about.
Further, according to an electric stapler using a linear staple, a staple sheet at inside of a staple cartridge is fed frontward by a staple feed mechanism and both sides of a staple other than a center portion thereof coming out from a staple outlet of the cartridge to outside is struck by a forming plate to form in a gate-like shape. A formed front staple is brought into a driver path having a predetermined lateral width formed at a guide plate on a front side and the staple is injected by a driver and at the same time, and when a staple at a successive row is formed by the forming plate and the driver returns to a standby position, a successive gate-like staple is fed into the driver path. At this occasion, when an attitude of the staple is inclined in a front and rear direction or a left and right direction, the driver cannot accurately strike a horizontal crown portion of the gate-like staple and the staple is buckled at inside of the driver path to clog. Therefore, in order to correctly maintain the attitude of the staple until striking the staple, a leaf spring is provided at a front end face on a side of the staple outlet of the staple cartridge, a front end portion of the plate spring is brought into elastic contact with the front wall face of the driver path and the staple is injected while rubbing the leaf spring by the staple and the driver to thereby prevent the staple from being inclined by the leaf spring.
The electric stapler of the background art maintains the attitude in injecting the staple by the leaf spring arranged at the driver path. However, there poses a third problem that since the staple and the driver pass the driver path by rubbing the leaf spring, a spring pressure of the leaf spring constitutes a drive load of the driver and loss of power and striking energy is considerable.
Further, there is a copier including an electric stapler simultaneously binding a plurality of locations of paper by a plurality of the electric staplers and there is a copier successively binding a plurality of locations of paper by moving a single piece of the electric stapler by a feed mechanism. Further, according to a copier constituted to laminate paper on the feed table by disposing a copy face of paper to a lower side for convenience of collation, in order to penetrate a staple from tail to head of paper, the driver unit of the electric stapler is arranged below the sheet table and the clincher unit is arranged above the sheet table. The staple guide of the driver unit is brought into a hole formed at the sheet table from a lower side to be brought into contact with paper face, the clincher unit on the upper side is moved down and pinches paper on the sheet table along with the staple guide and leg portions of the staple penetrating paper from the lower side are folded to bend by the clincher.
According to the copier in which the staple guide is made to advance into the hole of the sheet table in order to pinch paper on the sheet table by the staple guide of the driver unit and the clincher unit, and the single piece of the electric stapler is moved laterally by the feed mechanism, there is constructed a constitution in which a long hole in a lateral direction is formed at the sheet table and the staple guide of the driver unit is moved at in side of the long hole. Therefore, there poses a fourth problem that in feeding paper to the sheet table after having been processed by a copying step, a front edge portion of paper is caught by the long hole of the sheet table and a failure in feeding paper is brought about. Further, by forming the long hole at the sheet table, a bending strength of the sheet table is reduced and therefore, it is preferable that a dimension of the hole is as small as possible.
Further, the copier is arranged with a mechanism portion for traveling paper in a left and right direction to copy and discharge and copied paper is discharged to a tray provided at a left side face of the copier. A shaft of an electrostatic drum and a shaft of a feed roller of the copy mechanism portion are arranged orthogonally to a paper feeding direction and the included electric staple is arranged transversely in view from a front side of the copier in accordance with the direction of feeding paper.
Although the electric stapler is constituted by a structure of charging the staple cartridge from an upper side or a rear face side, inside of the copier is occupied by the copying mechanism portion and normally, there is not a space sufficiently for attaching and detaching the staple cartridge. Therefore, in interchanging the staple cartridge, a total of the unit of the electric stapler must be drawn out of the copier to this side by opening a front cover of the copier. Therefore, there is posed a fifth problem that time and labor is taken in operation of attaching and detaching the staple cartridge and replenishing the staple.
Further, the electric stapler is interposed with a suspension mechanism using a spring brought into contact with paper on the sheet table at the driver portion or the clincher portion which is constituted to absorb a difference in paper thickness by contracting the suspension mechanism in pinching paper by the driver portion and the clincher portion to deal with prints having various thicknesses.
A copier of a stapler including type is constituted to laminate paper on the sheet table by disposing a copy face of paper on the lower side for convenience of collation, the driver portion of the electric stapler is arranged below the sheet table and the clincher portion is arranged above the sheet table. Therefore, in this case, the suspension mechanism is interposed in the clincher portion, the clincher portion is moved down from the upper side to be brought into press contact with paper on the sheet table, the driver portion strikes out a staple from the lower side and leg portions of the staple penetrating paper are folded to bend by a clincher arm of the clincher portion to bind paper.
In the above-described electric stapler, there poses a sixth problem that when the clincher portion is brought into press contact with paper on the sheet table, an operating load for compressing the spring of the suspension mechanism is considerable and power consumption is considerable. Further, when the clincher portion is moved up after stapling, the suspension mechanism is released of being compressed to abruptly return to the initial state to thereby pose also a problem that mechanical noise is large.
Further, there is known an electric stapler of arranging the clincher portion and the driver portion opposedly to each other, pinching paper by the clincher portion and the driver portion and folding to bend leg portions of a staple injected by a driver by a movable type clincher. According to an electric stapler of this kind, the clincher portion and the driver portion are separated from each other. Therefore, there poses a seventh problem that high accuracy is requested in working and integrating parts in order to accurately coincide positions of the driver and the clincher. Further, when a position of the staple struck out by the driver is shifted frontward or rearward, a failure in clinching may be brought about since the clincher cannot normally clinch the staple.
Further, the electric staple included in the copier is constituted to pinch paper by the driver unit and the clincher unit separated upwardly and downwardly to staple and there is an electric stapler arranged with a plurality of sets of driver units and clincher units in accordance with positions of binding paper and there is an electric stapler of a moving type for moving one set of a driver unit and a clincher unit to staple a plurality of locations of paper.
According to the moving type electric stapler, the driver unit and the clincher unit are moved in synchronism with each other by timing belts respectively engaged with guide shafts. Initial stage gears or cams of drive gear mechanisms of the driver unit and the clincher unit are respectively fit slidably with two pieces of drive shafts of spline shafts or D-type section shafts or the like made to span in parallel with the guide shafts and by driving to rotate the two pieces of drive shafts, the driver and the clincher are driven via the gears or the cams to carry out binding operation. Further, there is also known a moving type electric stapler constituted to respectively mount motors to the driver unit and the clincher unit and carry out binding operation by controlling a traveling motor, a driver drive motor and a clincher drive motor by a control circuit.
When the moving type electric stapler is added with a corner skewedly binding function for striking a staple to a side of paper by an angle of substantially 45 degrees in addition to a back binding function of striking staples to a plurality of locations of a side of paper, there is needed a mechanism of rotating the driver unit and the clincher unit horizontally by about 45 degrees. In this case, according to a power transmission mechanism of the background art for driving the driver and the clincher by drive shafts made to span an interval of a frame, the driver unit and the clincher unit cannot be rotated horizontally relative to the drive shafts and therefore, it is general to construct a constitution of respectively mounting motors to the driver unit and the clincher unit and separately driving the driver and the clincher. However, there poses an eighth problem that according to the above-described constitution, in addition to the driver drive mechanism and the clincher drive mechanism, horizontal rotation drive mechanisms are respectively provided, the constitution is complicated to thereby bring about an increase in a number of parts, large-sized formation and an increase in cost.